Explosive-engine.



0. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED APR. 19. I912.

Patented Aug. 17, 1915.

8 SHEETS-SHEET 1.

COLUMBIA PLANOGRAPH 60-. WASHINGTON, D. c.

O. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED APR. 19. 1912.

1,1 50,244. Patented Aug. 17, 1915.

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COLUMBIA PLANOBRAPH co.,wAsHlNu:roN. I:v c

0. M. BERGSTROM.

EXPLOSIVE ENGINE. APPHICATION FILED APR-19.1912.

. 1,150,244. Patented Aug. 17, 1915. I I 8 SHEET$SHEET 3- 1 3 M W I COLUMBKA PLANOORAPH co..wAsHlNGTO .-D. c

0. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED APR. I9, 1912.

1 ,1 50,244. Patented Aug. 17, 1915.

a SHEETS-SHEET 5'. J

Zak z COLUMBIA PLANOURAPH 50-. WASHINGTON. D. c

O. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED APR. 19. 1912.

1,1 50,244. Patented Aug. 17, 1915.

I 8 SHEETS-SHEET 6. 4

Ill 1/% "12 Q 1? 5/ IV?! u 3 A wigs 5;; Ada/M. 50%;... MM,

COLUMBIA PLANOORAPH 60., WASHINGTON, D. c.

0. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED APR-19.1912.

1,150,244. PatentedAug. 17,1915.

IA/ i I}? I IIHIiI J HI 2 RAPH CO.,\VA$HINOTON, D-

0. M. BERGSTROM.

EXPLOSWE ENGINE.

APPLICATION FILED APR. 19. 1912.

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UNITED STATESJPATWT .orrrcn P OSCAR 1M. BERGSTROM, OF MINN EAPOLIS, MINNESOTA, ASSIGNOR TO UNIVERSAL MANUFACTURING COMPANY, OF..MINI\TESOTA. l

TdaZZ whom it may concern:

' Be it. known that I, Oscen M. a citizen of the "United-States, Minneapolis,

State of Minnesota, have inventedcertain BnResrnoM, residing at new and useful Improvements in Explosive Engines; and I dohereby declare the following to boa-full, clear, and exact description of the invention, such-aswil1 enable others skilled in the art to which it appertains to make and use the-same- My invention relates to internal combustion, or so-called explosive engines, and-has for its objectto generallyimprove the construction and operation-thereof.

Generally stated, the invention consists of.

the novel devices andcombinations of-devices hereinafter-described and defined-in the claims.

Hitherto, in explosive engines, puppet valves have, in someinstances, been dispensed with and replaced by-"a large sleeve working, as a valve, between the cylinder and piston, and in other instances,- by-a pair I of large concentric sleeves having the relation of primary and secondary valve acting elements, interposed between the cylinder and piston.- Both ofthesearrange ments have inherent disadvantages, certain of which may be statedgas follows: The necessary large diameter -of the sleeve or sleeves and the large number of wearing surfaces produces agreat amount of friction and a corresponding amount of wear; *The piston and interior of the explosion cham ber must' be cooled through the surround ing sleeve or sleeves, and this is very diiiicult. It is extremely difficult to maintain tight joints between the piston, cylinder and the interposedsleeves, and slight wear greatly increases the -tendency to leak,

Also, these large sleeves interposed between the cylinder and piston are expensive to' rapid and properly timed port opening closing movements, and when free from the objections above noted, makes possible an explosive or internal combustion. engineof very high efficiency and generally improved inth'e county of "Hennepin andv while the other "stands still.

.- plosions in the two chambers of 'der'. Gtherivise stated, there would be an or MINNEAPOLIS,- MINNESOTA, A CORPORATION EXPLOSIVE-ENGINE,

' Specification of Letters Patent. ,Pate f lvAug 17 1915. 7' 2 a iicatioiifiieda rn19,191a lserialNpxesi-ssr.

movement will be sirable features in mg primary and secondary valves, which are locatedouts'i'de of the engine cylinder where they have'noffrictional i tact I with the piston" oi"with the cylinder. These cooperating primary and secondary Valves are preferably inthe form of sleeves working, one within the other, and arranged for 're'cipro'cato'ry movement within a valve seat located immediatelyadjacent to the cooperating cylinder and "extendedparallel therewith; In connection with these valves, I- employ valve"actuatingmechanism, also, of novel construction and arranged, to impart differential movements to the said primary and secondary valves,"the"timing being such that at certain times,the two valves mo'vetogether asif one 'valve,and at certain other times, move at different speeds, and at other times, one of the valves will be moved tive movements are so timed that they give the most desirable and eflicient'fport'opening and closing movements, all as will hereinafter more fullyappear. Theimproved valve mechanism is adapted foruse in connection with either multicylinder or single cylinder engines, but is especiallydesigned and adapted for use in connection with' explosive engines of the four -cycletype: However, certain features thereof,"may be employed in connection with explosive enginesof theftwo cycle type.

My invention also involves as an additional jfeaturepf novelty, an arrangement ofxthe said improved valve mechanism in connection with differential cylinders and pistons. Inthis arran'gement, a single engine unit would comprise one differential cylinder and one differential piston, and the valvemechanism, when designed for cooperation'with afour-cycle engine of this differential piston-type would be arranged to control the-port openingsfor alternate exthe cylinexplosion 'fOreachQcQmpIete rotation of the engine crank shaft, and the explosions in the two chambers would be alternated. This arrangement makes possible an engine of maximum efiiciency in avery compact engine of minimum weight, size and cost.

engagement or con- 1 These rela-i The explosive engine illustrated in the drawings, is of the four-cycle type involving the differential cylinder and piston arranged to illustrate an engine which has been built and put into actual successful use.

In the. accompanying drawings which illustrate the invention, like characters inditaken on the irregular line m m on Fig. 1,

showing the improved explosive engine; Figs. 2 to 7 incluslve, are vertlcal sections but illustrating different positions of the f ferential cylinder and piston type,

Each cylinder casting is piston valve mechanism, some partsbeing shown in full and some parts belng removed and Fig. 8 1s a vert1cal section taken 2 on the irregular line his-m on Fig. 1.

The engine illustrated in the drawings is, as already indicated,of the four-cycled f and Fig. 1 illustratestwo units, thatis, two differential cylinders 1, each cylinder having two explosion chambers 1 and 1?, the said cylinders, as shown, being iwater-lacketed. formed with two long cylindrical valve seats'2 and 2 that extend parallel to the cylinder axls, as close as practicable to the inner cylindrical surfaces and explosion chamber thereof. Each cylinder is provided with a large-port 3 that opens from its explosion chamber l intothe cooperating valve seat 2, and with a similar port 3 that opens from its explosion chamber 1- into the cooperating valve seat 2. The valve seats'2 and 2 are provided, respectively, with intake ports 4 and 4: that connect to an intake manifold 5. The upper extremities of the valve seats 2 and'2 serve as exhaust ports and are all connected to an exhaust manifold 6. As shown, the

- two differential cylinders 1 are cast in tegral, and they are connected to acommon.

base.7 having a crank shaft casing'8, the

chief function of the latter of which is, to

contain oil. In the top of each cylinder is an ordinary sparking plug seat 9 opening intothe respective explosion chambered, andv similar sparking plug seats, not "shown, will open into the sides of the cylinders into the respective explosion chambers 1 The sparking plugs, not shown, may be of any suitable construction'and for the purpose of this case need not be further considered. Working in each differential cylinder 1 is a differential piston 10.v Thetwo differ: tial pistons 10 are, byv connecting rods 11, connected to cranks 12 ofv an engine crank shaft 12 that is journaledin suitable bear-I ings formed in part on the base of the cylinder casting, and, in part,.onthe upper portion of the base casting 7 .7 The cranks 12 for the. two differential pistons, will usually'be set 180 degrees, the one ahead of the other. Located in the lower portion of the casing 8, 'journaled insuitablefbearings on the sides thereof, and having its axis parallel to the axis of the {crank shaft 12, is a valve actuating crankshaft or cam shaft 18.. The engine crankshaft 12"carries a spur pinion 14 that meshes with the spur gear 15 on one outer end of the valve crank shaft 13.- The gear 15 is twice the diameter of the pinion 14, so that the said valve actuating crank shaft 13 will be given one. complete rotation for each two complete .rota

tions of the engine crank shaft. For each differential cyl'ndcr, the crank shaft 13 is provided with a cam or eccentric acting crank 16, there being, of course, two ofthese cranks. in the eng ne illustrated, both of which are located within the casing 8. These cranks '16 are set 180 degrees, theone ahead of the other.

Working in ea h'valve seat 21in direct contact therewith, is an outer valve sleeve or so-called primary valve sleeve 17, and working within each primary valve 17 is an inner valvesleeve, orso called secondary valve 18. The primary; valve 17 is opened both at its vupper and lower ends, but said secondary valve is closed bothat its upper and lower ends. The primaryv valve 17 is provided with ports 19 a'ndi20, and the secondary valve 18 is provided with ports 21 and 22. r Theports 19 and 21 and the ports 20 and 22 are adapted to bemoved into registration at the proper times by longitudinal sliding movements of the said valves, in respect to each other.

The valves 17 arranged forcoiiperatio-n with the 'ports 3 and 4, respectively, of the cylinder casting, and control the admission and exhaust toand from the explosionchamber1?,while the valves 17 and 18, which are within the and 18 in the seats 2 are valve seats 2*, are located higher up and c 7 are arranged forco'tiperationwiththe ports 3 and 1 of the cylinder casting and control the admission and exhaust to and from the explosion chamber 1 The lower'. ends of the valves 17 and 18 are COIlIlQCtGdbYI rods 23 and 2 1, respectively, to valve actuatng levers 25 and 26, which, as shown, are intermediately pivoted on the fulcrum rod 26, extended through the'lowerportion of. the crankshaft chamber 8 and suitably sc cured to the sides thereof. The said' levers [25 and some located side by side in pairs,

and they are provided withfbifurcatedor I forked heads that embracelthe crank" 16.

In Figs. 2 to 8 inclusive, the axis of the valve actuating crankshaft513-is indicated I at 18. The prongedheads of bothlevers 25 and 26 areformed with parallel and coincident crank engaging-surfaces 27. {Out-f ward ofthe saldsurfaces 27, the lever 25 is formed with parallel, upwardly, inclined crank engaging surfaces 27}, and the lever; 26 lsformed with parallel downwardly 11 .r" r

, stated, however,

clined crank engaging surfaces 27 It is important to here note thatthe cam surfaces 27* of'the lever25 extend in anabrupt angle to and crosswise of the cam surfaces 27 of the lever26. This produces a peculiar and highly important valve movement which will presently appear. It may :be here that when the common crank 16 is operated on the coincidentpan secondary valves 17 allel cam surfaces 27 of the two levers'25 and 26, the said two leverswill move in unison,- or as if one, and the primary and and 18 will, likewise, move in unisomor as if one. On the other hand, when the said crank 16 operates simultaneously upon the reversely' inclined or extended crank surfaces 27 and 27, the said levers 25 and 26, and hence, the primary and secondary valves, will be given very different movements.

. Operation: The following description of the operation will follow only the action of the valves 17 and 18 in their control of the admission and exhaust into and from the lower explosion chamber 1 of one cylinder. Attention'is first calledto Fig. 2, which shows the position of the differential piston and the primary and secondary valve 17 and 18, approximately at the'time of ex plosion, it being, of course, understood, that the explosion may take place either slightly before or slightly after the crank has reached its upper dead center, illustrated in Fig. 2. The engine crank shaft moves in the directionof the arrow marked thereon in ig. 2 and in other views, and the valve actuating crank shaft 13 rotates in a reverse direction at one-half the speed. In the position of the valve shown in Fig. 2, the port 19 of the primary-valve is closed by the secondary valve 18 and there is an extended lap of the primary valve upward past the cylinder port 3, so that the explosion chamber 1 is securely closed against the escape of gas at. this time. Under the force of the explosion, the piston is moved downward and the crank shaft rotates about 135 degrees, to-wit, approximately to the position indicated by the dotted line g on Fig. 3, before the cylinder port 3 is uncovered to exhaust, by the upper end ofthe primary valve 17. .When the crank reaches itsgfirst downward dead center, shown in Fig. 3, the port 3 has been well opened to exhaust, but the extreme opening ofthe said port takes place when the crank has moved about 90 degrees beyond the position shown in Fig. 3,towit, into the position shown in Fig. 4. During this much, to-wit, during approximately the first 225 degrees of the engine crank shaft movement, the valve actuating crank 16 of theshaft 13, engages with the coincident surfaces 27 of the twolevers 25' and 26,- so that, *up to" this time, the two valves 17 and 18 are moved downward tohaust or scavenging tively, and during this time,

crank shaft movement past full registration,

gether at the same rate of speed and will act as a single valve. Further rotary movement of the engine crank shaft from the position shown in :Fig. l,toward and to the position shown in Fig. 5, completes the exaction, and it will be here noted that the exhaust takes place during approximately 225 degrees of movement of the engine crank shaft. This gives a good chance for complete scavenging action. VVhile the engine crank shaftmoves from the position shown in Fig. linto the position shown in Fig. 5, and to approximately degrees beyond the position shown in Fig. 5, the crank 16 of the shaft 13 operates on the oppositely diverging cam surfaces 2'? and 27 of the levers 25 and 26, respecthe secondary or inner valve 18 is held approximately in a stationary position, while the primary valve 17 is moved rapidly upward. The said primary valve closes the cylinder port 3 from exhaust 'apprbximately in the crank shaft position shown in Fig. 5, but continues theupward movement of the" said primary valve for about 45 degrees of the engine the position shown in Fig. '5, thus giving one lap. "When the engine crankshaft commencing its second rotation, passes slightly beyond the position shown in Fig. 5, the cylinder port 3will be closed to exhaust and open to admission, but the full opening of ports to ad mission does not-take place until the engine crankshaft is moved approximately 90 de grees on its second rotation, or to the position'shown in Fig. 6, at which time, the ports 19 and 21 of the valves 17 and18, register with each other and with the cylinder port 3, and the valve ports 20 and 22 register with each other and with the admission or intake port 4. lVhen the engine crank shaft moves inward from the position shown inFig. 6, l7 and 18 move together with the ports in thus giving a full admission. Theclosing of the admission ports is not completed, however, until the engine crank shaft, continuing its second rotation, moves to the position about 20 yondthe position shown in Fig. 7.

gme is, therefore,

The enopen to admission of the explosive ga or vaporfor little more than 180 degrees of engine crank shaft movement, and the compression takes place during the remainder of the second rotation. of the engine crank shaft, to-wit, during approximately 160 degrees of the engine crank shaft movement, at which time, of course,

thecomplete cycle of operation has been completed and the ports again stand in the position shown in Fig. 2, ready for the next explosion or just subject to an explosion.

. A already stated, when the engine crank is moved from the position shown in Fig. 2,

about degrees, the two valves,

degrees bepast the position shown in Fig. 3, and into theposition shown in Fig. 4, the two valves 17 and 18 move downward together; Also, it will be remembered that when the said engine crank shaft moves from the position shown in Fig. 2, approxlmately to a posi-z two valves again assume the overlapped posltlon,

with all ports closed, shown in Fig. 2. A double overlapping or closing of the ports to resist the explosive force is afforded at the time of explosion. Furthermore, the rapid opening and closing of the ports is accomplished and. larger port openited to the use of differential cylinders-and ings are maintained for the greatest possible length of time. 7 i

In the exhaust and admission opening movements, the valve controlling movement is as rapid, and at certain periods, more rapid than the piston movement. This rapid valve movement is due,'partly to the oblique cam surfaces of the valve actuating levers and is due partly to the speed multiplying movements of the said'levers. In fact, any de sired rapidity of valve movement may be obtained by the proper proportion of the said levers. In a'two-cycle engine, with the valve actuating crank rotation only onehalf as fast as the engine crank shaft, the valve actuating movement, unless multi- V plied, would be very slow, but in my invention, the valve actuating movement may be multiplied to any extent found desirable. The levers shown, are of the first class,.but may, of course, be either of the second or third class.

The Valves 1'? and 18 which control admission and exhaustto the upper explosion chamber 1 of the differential cylinder, op-.

erate in their cycle or actionjust as do the valves 17 and 18, above described, but their actuating crank 16, being set 180 degrees from the actuating crank 16, representing one rotation of the engine crank shaft, causes the explosion in the said chamber 1.

I and all the other steps of the .cycle, to take place just one rotation of the crank shaft ahead of or behind the corresponding cycle actions which take place in the lower chamher 1". This, as is evident, gives one explosion in its differential cylinder and 'of carbon within the engine.

each comof combustion and thus assists in keeping the'engine cool, also, prevents "accumulation The continued full-opening of the admission-ports insures a good vapor. cold gas or explosive vapor through the primary and'secondary valves, serves to'keep down the temperature of the said valves.

charge of fresh; gas or, explosive Also, the very actof drawingthe .75

The exhaust gases, it 'will be noted, are not, in this preferred arrangement, passed 1 through the valves, but-mare simply passed over the tops of the, same, and hence, have a minimum tendencyfto heat the same. The so called primary and. secondary valves are preferably of sleeve-like form and are arranged to reciprocate, one within the other, and the outer vwithin its valve seat, but the invention may be modified in this respect, and the said valves might be'given oscillatory or reciprocatory movements.

As herein already made clear, the broad features of this invention are not at all limpistons. cylinders and therewith, with improved valve involves novelty of high importance, certainadvantages of which have already been stated. It may be further stated, however, that the use thereof gives an explosive engine of compact form, few parts, economical construction, and in which there is a perfect mechanical and explosive balance.

VVhatIclaim'is: 1. Inan explosive engine, the combination with a cylinder, a piston, an, engine crank shaft and connecting rod, of a valve actuating crank shaftdrivenfrom said "engine shaft, a valve cooperating with ports in said cylinder, and a lever'connected to said valve and having a bifurcated portion with cam surfaces actuat d by said valve actuating 2. In an explosive engine,.the combination with a cylinder, a piston, an engine crank shaft and connecting rodyof a valveactuating crankshaft driven fromisaid e'ngine shaft, a valve cooperating with ports in said cylinder, and and having a bifurcated portion with angular or crooked cam surfaces actuated by said valve actuating crank.

a lever connected to said valve 3. In a four-cycle explosive enginep the" combination with a cylinder, a piston, a

crank shaft,and connecting rod, of a valve actuat ng crank drlven fromsaid engine crank shaftiat one-half thes'peed thereof,

valves controlling admission and exhaust to and from said cylinder and-pair 'of levers independently connected to said valves, said two levers having bifurcated portions with cam surfaces subject to said valve actuating crank, said cam surfaces of said two levers being coincident in part, and extending at an angle to each other in part, whereby similar movement will be imparted to said two valves at certain times and differential movements imparted thereto at other times.

4. In a four-cycle explosive engine, the combination with a cylinder, a piston, an engine crank shaft and connecting rod, of a valve actuating crank driven from said engine crank at one-half the speed thereof, co-

operating sleeve-like primary and secondary valves working, one within the other, and

Copies of this patent may be obtained for controlling admission and exhaust to and from said cylinder, and a pair of levers independently connected to said two valves, said two levers having bifurcated portions with cam surfaces, the said cam surfaces of said two levers in part being co-incident, and in part extending at an angle to each other, whereby said two valves will be given like movements at certain times and diiferential movements at certain other times.

In testimony whereof I affix my signature in presence of two witnesses.

OSCAR M. BERGSTROM. Witnesses:

BERNICE G. WHEELER, HARRY D. KILGORE.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

